Sciencemadness Discussion Board

Stupid stuff I found on Khan Academy

MrFormula - 30-9-2024 at 06:56

Hi, I was looking through my email and I found a screenshot I sent to my friend when I was just starting out in chemistry. I thought you all would think this is simultaneously hilarious and terrifying. Enjoy!




[Edited on 9-30-24 by MrFormula]

Screenshot 2023-11-02 10.58.08 AM (1) (1).png - 46kB

DraconicAcid - 30-9-2024 at 07:43

Yikes!

Jenks - 30-9-2024 at 18:47

I don't get it.

j_sum1 - 30-9-2024 at 20:36

Not what I would call wrong, but definitely not the example i would use. Or maybe not the phrasing I would use for this question.
I would probably say, "Based on patterns in the periodic table, predict the substance that has properties most similar to CaCl2."

As it turns out, both CaCl2 and MgCl2 may be used for the production of Tofu.
From Wikipedia:
Quote:
In the food industry, calcium chloride is frequently employed as a firming agent in canned vegetables, particularly for canned tomatoes and cucumber pickles.[17] It is also used in firming soybean curds into tofu and in producing a caviar substitute from vegetable or fruit juices.[17]

Quote:
Magnesium chloride (E511[19]) is an important coagulant used in the preparation of tofu from soy milk.

I would tend away from foodstuffs as a subject for extrapolating properties. I just think that is unwise. But, there may be some people into thallium oxide dinnerware.

My phrasing of the question still works. You are after a substance that is ionically bonded, with a group 2 cation, and a group 17 anion. Process of elimination allows you to reject all other options.

In my view however, tofu is not food. So, perhaps it does not matter.

unionised - 1-10-2024 at 05:33

Needs a tie-in with this thread.
http://www.sciencemadness.org/talk/viewthread.php?tid=160521

MrFormula - 1-10-2024 at 06:47

Quote: Originally posted by Jenks  
I don't get it.


The joke is that the first chemical (carbon tet) is a possible answer to treat soy milk. Granted it is wrong but it's funny that it's there in the first place.

Precipitates - 1-10-2024 at 19:34

Nothing like a nice bit of tet milk! :D

Enriched soy protects against the toxicity of CCl4, although you still wouldn't want to purposefully add carbon tet to your milk.

MrFormula - 2-10-2024 at 08:41

Quote: Originally posted by Precipitates  
Enriched soy protects against the toxicity of CCl4, although you still wouldn't want to purposefully add carbon tet to your milk.


Wow. I didn't realize that was actually something people did. I thought it was just a bit of Khan academy weirdness.

Precipitates - 3-10-2024 at 18:24

CCl4 is used for inducing liver injury e.g.,

The carbon tetrachloride model in mice

I've been watching a few of the old Carry On movies lately, and coincidentally read this (edited slightly for clarity):

"On 14 October 1962, Kenneth Williams' father, Charlie Williams, was taken to hospital after drinking carbon tetrachloride that had been stored in a cough-mixture bottle. He died the following day."

Kenneth Williams wiki page

rodster - 18-10-2024 at 10:51

speaking of khan academy I posted about them awhile back.

https://www.sciencemadness.org/whisper/viewthread.php?tid=16...

Basically, they completely revamped one of their chemistry courses recently, and if you look
at the archive link vs the live link, their course listing was much more comprehensive than it is
now, so it's like they decided to scale it back from being a full course (as maybe they didn't have faith in
it)

I kinda lost faith in them after this.